The present invention relates to a mold head of spring forming machine for bending wires that makes spring, and more specifically to a mold head capable of bending the wires with different radii of curvature for making springs of different specifications.
A conventional spring forming machine feed wires that make springs by means of transportation rollers. A first bending operation is performed on a predetermined length of the spring wire to form a curved hook of a predetermined angle. The length of the wire is then swirled to form helical configuration. Thereafter a second bending operation is performed on an opposite end of the length of the spring wire to form another curved hook. By cutting the spring so formed off the spring wire, the spring product is completed.
In order to make springs having curved hooks of different bending angles, many sets of bending tools of different specifications are required. This complicates the spring forming machine and increases costs thereof.
Spring forming machines comprising a single computer-controlled bending tool for forming curved hooks of different bending angles are known, which allows for formation of different curved hooks with a single set of bending tool. Such spring forming machines, however, has disadvantages, such as:
(1) Although the curved hooks of different bending angles can be formed with a single set of tool, it still requires a number of different mold heads for forming curved hook having different radii of curvature. The costs are still high.
(2) The mechanism required for controlling the bending operation of the spring wire is complicated, leading to high costs.
It is a purpose of this invention to provide a mold head device of a spring forming machine. The mold head can be assembled and reassembled easily. The mold head has a plurality of chunk blocks each having rounded corners of different radii of curvature, allowing a spring wire to be bent with different radius of curvature. The unique mold head could replace the traditional complicated forming machine and save a lot of expense.
It is another purpose of this invention to provide a mold head device of a spring forming machine, wherein the mold head device comprises a rotation mechanism for rotatably driving a rotation head and a linear motion mechanism for linearly and axially moving a mold head. The mold head has a plurality of chunk blocks defining therebetween channels for accommodating a spring wire. Each chunk block has rounded corners of different radii of curvature. The rotation head has a projection capable to engage and drive an end of the spring wire to rotate about the rounded corner of the chunk block to form curved hook having radius of curvature corresponding to that of the rounded corner.
The above problems are at least partially solved and the above purposes and others are realized in a mold head of a spring forming machine shown as follow:
The present invention relates to mold head device of a spring forming machine. The device comprises a rotation mechanism, a linear motion mechanism, a rotation head and a mold head. The rotation head has a projection and can be rotated by the rotation mechanism. The mold head is fixed to a center shaft of the linear motion mechanism and can be driven back and forward linearly. The mold head has a plurality of chunk blocks, wherein diametrically extending channels are defined between the chunk blocks. Each corner end of each chunk block is contoured as an arc having different radii of curvature. To bend an end of a spring wire, the linear motion mechanism moves to have the spring wire received in one of the channels. Furthermore, the rotation head swirls in accordance with the rotation mechanism and uses one of the chunk blocks as a pivot, theprojection of the rotation head providing a bending force on the spring wire and bending the spring to a certain angle.